In the testing of electronic components and circuits, a test probe is typically used to make contact with the circuit element being tested. The test probe is typically connected to the test apparatus itself by means of a test lead. The test probe may be positioned manually by an operator or it may be positioned and then repositioned automatically in a specific, controlled sequence, such as occurs in automatic test equipment (ATE) apparatus, which is designed to test complete circuit boards in a short period of time.
The circuit board being tested must be supported on a test bench or in a fixture of some kind. Occasionally, such fixtures will also include a means for controlling the movement of the test probe or probes. In a typical ATE, a computer program will control the movement of the test probe or probes. One known configuration includes a set of probes which are lowered to touch all of the test points on the circuit board, referred to generally as a "bed of nails" approach. However, such existing test fixtures are unsatisfactory in many applications; they are often difficult to use and they are expensive. Most existing test fixtures, particularly those which are less expensive, do not have the capability of reliably and repeatedly clamping the circuit boards for testing within required tolerances for automatic testing. Thus, a significant need remains for a test fixture which is simple to use and relatively inexpensive, but which provides reliable and repeatable positioning of printed circuit boards and the like within the required tolerances for subsequent circuit test procedures.